Dehydrater.



l/9i by gooc a C. ROBINSON.

DEHYDRATER.

APPLICATION FILED NOV. 29. 1910.

Patented Dec. 12, 1916.

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c. ROBINSON.

' lo Patented Dec. 12, 1916.

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DEHYDRATER. APPLICATION FILED NOV. 29,1910.

Patented Dec. 12, 1916.

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CYRUS ROBINSON, OF MOUNT VERNON, NEW YORK, ASSIGNOR TO METALLURGICALENGINEERING & PROCESS CORPORATION, A CORPORATION OF NEW YORK.

DEI-IYDRATER.

Specification of Letters Patent.

Patented Dec. 12, I916.

Application filed November 29, 1910. Serial No. 594,704.

To all whom it may concern Be it known that I, CYRUS ROBINSON, a subjectof the King of Great Britain and Ireland, residing at Mount Vernon, inthe county of Nestchester and State of New York, have invented certainnew and useful Improvements in Dehydraters, of which the following is aspecification, reference being had therein to the accompanying drawings.

This invention relates to improvements in filtering or dehydratingmachines and is especially adapted for use in separating the moisturefrom ore pulp during processes of extracting the metallic values fromore by means of chemicals, such as potassium cyanid.

The invention relates more particularly to that class of machines inwhich a rotating drum or equivalent structure is used for supporting afiltering medium, and in which the filtering medium when so supported isalternately subjected to the action of suction and of air pressure.

The objects of my invention'are to pro vide a machine of this generalcharacter having various improved structural features, improved meansfor controlling the vacuum and air pressure, and improved means forremoving the filtered material from the surface of the filtering medium.

Further objects will appear from the following specification.

In the accompanying drawings I have shown the form of my invention whichI at present deem preferable, but many changes and modifications withinthe scope of my invention will be apparent to those skilled in the art.

Of the drawings, Figure 1, is a plan view of a mechanism embodying myinvention. Fig. 2, is a view showing one end. ,Fig. 3,

is a view showing the. other end. Fig. 4, is a a side view partly inelevation and partly in longitudinal section along the central plane ofthe machine. Fig. 5 is an enlarged end elevation of the rotatingdrumwith certain adjacent parts, portions of the drum being shown in crosssection. Fig. 6 is an enlarged fragmentary cross sectional view takenalong. the line 6-6 of Fig. 5. Fig. 7 is a plan view of the wooden partsof'one of the filtering sections. Fig. 8 is an enlarged fragmentarycross sectional view showing' part of the frame work and adjacent partsfor supporting the filtering medium taken along the line 88 of Fig. 4.Fig. 9.is a

dehydrated. The solution on pulp to be treated may be led into the tankby any suitable means such as a pipe 2.

The lower part of the tank may advantageously be constructed of concreteas indicated in the drawings and the upper part may advantageously beformed of sheet metal 3 reinforced at the top with an .angle iron 4. Thetank is shown cylindrical in form though it will be understood that thisparticular shape is not essential.

5 represents as a whole a hollow shaft which extends horizontallythrough the cen ter of the upper part of the tank 1. The shaft ismounted in bearings 6, (3,which may, if desired, be arranged to engagewith it only at the lower side as indicated in the drawings. Stuffingboxes 7, 7 are provided to prevent leakage of the solution or pulp atthe 1 points where the shaft extends through the tank walls.

A suitable mechanism is provided for rotating the shaft and the partsattached to it, which will be fully described hereinafter. This rotatingmechanism for the shaft may conveniently be a worm wheel 8 and a worm 9mounted upon a shaft 10 which is operatively connected to any desiredsource of power.

The shaft 5 is preferably made in three sections, the end sections 11,11, being necessarily hollow and the central section 12 being alsopreferably hollow to reduce the weight. Each of the tubular end shaftsections is preferably tapered toward its outer end. The inner end isprovided with an enlargement or hub 13 having its periphery composed ofa number of small fiat faces tions 11, 11, are stationary pipes 17 and18.

Stufling boxes 19, 19, are used to insure proper communication of thepipes with the interiors of the shaft sections without leakage. One ofthe pipes, as for instance 17, is connected to a suitable device forproducing a partial vacuum, and the other pipe, as

for instance 18, is connected with a suitable device for supplying airor other gas under pressure. The purposes of these suction and airsupply pipes will be later fully set forth.

number of hollow spokes 20, 20, are provided. In the drawings nine suchspokes are indicated as connected with each of the hollow hub-s 13, theinner end of each spoke being fastened to one of the faces 13 of thehub, with the passage through the spoke in register with thecorresponding aperture 14. These spokes may advantageously be formed ofsections of piping to the ends of which are secured flanges of standardform.

At the outer ends of the spokes of each set there is secured an annular,tubular ring or combined conduit and frame 21. This is preferably formedof cast iron in sections 22, 22, as many sections being provided asthere are spokes. The ends of the adjacent sections may be provided withflanges through which pass bolts for connecting the sections together.Each section is provided with a hollow flanged boss 23, which isconnected with the outer end of a spoke and I and 8, it willbe observedthat a taperingwhich serves to establish communication between theinterior of the spoke and the interior of the section. It will be notedthat the sections connect with each other and thus free anduninterrupted communication. is provided not only between" all parts ofthe conduit or frame 21, but also, through the spokes 20, between theconduit and the interior of the corresponding shaft section 11.

Each of the conduit or frame sections 22 is'provided with a number ofradially inward projecting bosses 24, 24. In-the drawings five suchbosses are shown for each section. --As the constructions of all ofthese bosses and of the parts connected therewith 0 are similar, .a,detail description of one of them will be suflicient.

I Referring more particularly to Figs. 6

aperture 25 isprovided which extends transversely of th'e conduitsectionthrough the boss 24. Passage-ways 26 and 27 are provided througheach boss to the aperture 25, one of these passageways 26 communicatingwith the interior of the conduit and the other passageways 27 with theexterior at the periphery. Rotatably mounted within the aperture 25 is acorrespondingly tapered valve plug or spigot 28, having a diametricalpassage 29. It will be noted that the passageways 26 and 27 form ductswhich extend radially outward from the conduit to the filter sections.These ducts are opened and closed by the valves. The spigotmay be heldin place by a washer 30 and a nut 31, engaging its threaded end. Theother end of the spigot is provided with a star wheel 32 having fourarms. The purpose and function of the star wheel will he hereinafterfully set forth.

33 represents as a whole one of the filtering sections or pans which aresecured to the frames 21, 21, and which, taken together, form acontinuous drum or cylinder. As many of these sections are provided asthere are bosses 24 and spigots 28, in this case there being forty-fivesections in all. As these filtering sections or pans are of similarconstruction, a particular description of one of them will besufficient.

As a framework for each filter section there are provided two parallelbars 34, 34, which extend the full length of the drum. They arepreferably made of wood. Cross bars or blocks, 35, 35, extend betweenthe bars at their ends and a similar cross bar or block 36 extendsbetween them at their centers. Each of the blocks 35, 35, and 36,

is of the same thickness as the bars 34, 34,

and is notched to receive the correspondingly notched bars, as is shownin Figs. 6 to 8. Outstanding flanges 35, 35, are provided at the outeredges of the blocks 35, 35. Blocks 37 37 similar to the block 36 alsoextend between the bars 34 and 34, and are positioned to be detachablysecured to the conduits or frames 21, 21, by means of flanges 38, 38,and bolts 39, 39. All of the blocks 35, 36 and 37, are preferably formedof some hard wood such as lignum vitae.

The frame work which has been described is covered between the flanges35", 35, with a rolled metal sheet 40, which may for the sake ofconvenience be made in two parts connected by a butt strap 41, as shownin Fig. 10. The edges of the sheet 40 are bent inward to engage theedges of the bars 34 and the cross blocks. Outside of the sheet 40 is asecond sheet of metal 42 which is given a series of longitudinalcorrugations 43, 43, and which is also bent inward to contact with theinward bent edges of the sheet 40, The sheet 42 may also be in two partsconnected by a butt strap 42. The sheets 40 and 42 maybe secured inplace by means of screws 42 at the bottoms of the corrubottoms of thebars 34, 34. It will be observed that by means of this construction thecanvas is supported along a series of separated parallel lines. In thisway there are formed beneath the canvas and between the adjacentcorrugations longitudinal passageways 45, 45, which extend the entirelength of the drum.

Each of the cross blocks 37, 37, is provided with a groove 46, whichextends transversely of the filter pan or section. An

opening 47 establishes communication between the groove and the opening27 leading from or to one of the spigots 28. Apertures 48, 48, areprovided in the metal sheets 40 and 42, at the bottoms of thecorrugations, and establish communication between the groove 46 and thegrooves or passageways 45, 45. In this way, therefore, unbrokencommunication is established when the spigots are open, between theconduit 21, and the grooves or passageways 45, 45.

When all of the filter pans or sections are in place on the framework,they may be secured together by means of bolts 49, 49, extendingtransversely through each pair of adjacent bars 34, 34. i

50 represents a framework at one end of the machine which may beconveniently mounted directly upon the angle iron 4 on the top of thetank section 3. This framework comprises preferably two I-beams 51 and52, which extend at right angles to the main shaft. Mounted upon theseI-beams are other smaller I-beams 53 and 54, which project within thedrum and carry tie-plates 55.

56 is a bracket secured to the upper tie- 'plate 55 and is provided atits upper end with a grooved slot concentric with the drum itself. Inthis sl t a pin 57 is adjustably mounted and held in place by means of anut. This pin is adapted to engage the arms of the spigot star wheel 32,as the drum is turned. By this engagement with the pin 37 the starwheels are turned through an angle of 90.

58 represents a second bracket similar in function to the bracket 56 butdiflerently shaped and secured to the lower of the two tie plates 55connecting the I-beams 53 and 54. It is similarly provided with a curvedslot concentric with the drum. In this slot there is mounted a pin 59similar to the pin 57 and similarly held in adjusted position by meansof a nut. This pinalso by engagement with the spigot star wheels servesto rotate them through an angle of 90,

beams 52, 52.

It will be understood that the opposite end of the machine is providedwith a similar frame work and with similar devices for operating thespigot star wheels. These devices are indicated in Fig. 3, and a detaildescription of them will not be necessary.

At the forward side of the machine, that is, at the side toward whichthe drum rotates, there is mounted a trough 60, the bottom of which isinclined toward one end of the machine. This trough may be convenientlysupported upon the I-beams 52 by means of frame structures such as areindicated by 61. The lower end of the trough may be connected with anysuitable means such as a second trough 60 for carrying away the mixturewhich is received by the trough 60 in the manner to be hereinafterdescribed.

Bearings 62 are mounted upon the frame parts 61 and for the purpose ofsupporting these bearings channel irons 63 may be provided.

64 represents a scraper or deflector plate which extends the entirelength of the drum and which is provided at its forward edge with aflexible lip 65 which may preferably be formed of sheet rubber. This lipis adapted to engage with the filtering surface of the drum.

As shown in the drawings the plate 64 is mounted upon an Ibeam 66, andthis I-beam is provided at its ends with cylindrical trunnions 67 whichare supported in the bearings 62. In this way the plate 64 is pivot'allysupported with its rubber lip in operative position. If desired, inorder to provide a. means for regulating the pressure of the rubber lipagainst the drum, an arm 68 may be secured to one of the trunnions 67,and upon the arm there may be mounted a slidable weight 69 provided withmeans such as a set-screw 70 for securing it in adjusted position on thearm.

Above the drum and directly back of the scraper or deflector beforedescribed there are mounted a plurality of pipes 71, 71, which extendthe entire length of the drum. In the drawings I have indicated threesuch pipes though the actual number may be varied in accordance with theconditions under which the machine is to operate. The pipes may bemounted upon suitable frame structures such as are indicated by 72 andwhich in turn are supported from the I- Each of the pipes is provided inits lower side and throughout its length with a series of smallapertures. The pipes are connected at one end with a manifold 7 3through which a suitable liquid, such as water, or a chemically ac-.tive solvent, may be introduced into the .Llu

jso

provided below and in front of the edge of the scraper. This pipe may besimilar to the pipes 71, 71, and may be similarly connected with themanifold 73. If the supplementary pipe 74 is used, I prefer to providebelow it a second scraper or deflector 64 similar to the scraper 64 andsimilarly provided with a flexible lip 65*. The scraper 64 may bepivotally mounted as shown in the drawings and may be provided with anarm 68 upon which there is a slidable weight 69 held in adjustedposition by means of a set screw 7 O.

The operation of my improved dehydrater is as follows, it being assumedfor pur poses of illustration that it is used to perform one step in thetreatment of ore by the potassium cyanid process: Let it be consideredthat a mass of pulverized ore has been intimately mixed with andthoroughly subjected to the action of a solution of solvent. After thisstep of the process has been completed the pulp or mixture of ore andsolvent solution is led into the tank 1 through the pipe 2. The inflowof pulp should be so regulated as to keep the level of the mixture nearthe top of the tank and at the same time prevent overflow. The drum iscontinuously rotated in the direction of the arrows on the variousfigures of the drawings by means of the worm wheel 8, and the worm 9.The speed of rotation may, of course, be varied in accordance withconsiderations as those depending upon the character of the pulp to betreated. However if a drum of, say, 18 feet in diameter is used, I atpresent consider that a rotative speed of one revolution in ten minuteswould insure a satisfactory operation of the machine under averageconditions.

The shaft section at one end of the machine, for instance the left handend, is connected by means of a pipe such as 17 with a suitable vacuumpump. By this means a constant vacuum is maintained within t-he lefthand shaft section, within the spokes 20 connected to it and within theleft hand annular conduit 21. Similarly, the shaft section at the otherend of the machine is connected by means of a pipe such as 18 with adevice for supplying air under pressure. In this way a constant pressureis maintained within the right-hand section, within the spokes 20connected to it, and within the right-hand annular conduit 21.

Referring to Fig. 5, it will be observed that the spigots 28 in theleft-hand conduit 21 are in open position with the exception of thosewhich are situated between the pins 57 and 59. Therefore directcommunication is established through the spigots between the conduit 21and the passageways or grooves 45 immediately beneath the canvas filtersurface, a vacuum being thus formed in the grooves or passageways. Theliquid eonstituent of the pulp in which the drum is partly submerged isdrawn inward through the filtering medium and the solid constituents ofthe pul are collected upon the outer surface of the filtering medium.The liquid thus drawn out from the pulp mass will pass from the grooves45 through the various passageways which have been heretofore describedand out through the pipe 17 to be,

afterward treated in any suitable manner.

It will be understood that the corresponding spigots at the other orright-hand end of the machine, 2'. 6. all of them except those betweenthe pins 57 and 59, are in closed position, communication being thus cutoff between the grooves or passageways 45 and the air pressure device.When, by the constant rotation of the drum, the spigot star wheels arebrought successively into engagement with the pins 57 located atopposite ends of the machine those spigots at the lefthand end of themachine are moved from open to closed positions and those at theright-hand end are moved from closed to open positions. Similarly, whenby the continued movement of the drum the spigot star wheels are broughtinto engagement with the pins 59 at the opposite ends of the machine,those at theleft-hand end of the machine are moved from closed to openpo- 9 sitions and-those at the right-hand end are moved from open toclosed positions. By means of this mechanism, therefore, that part ofthe filtering medium which is at any time positioned between the planesof the pins 57 and 59 is subjected to outward air pressure, while theother part of the filtering medium not so positioned is at the same timesubjected to suction or inward air pressure. The suction serves to drawthe moisture from the pulp and effect the filtering operation, while thepressure serves to loosen the solid material from the surface of thefiltering medium. The continued action of the vacuum after the filteringmedium emerges which the respective sections of the drum i are connectedwith or disconnected from either the vacuum means or the pressure meansmay be adjusted at will within certain relatively small limits. This maybe done by changing the positions of the pins 57 and 59. For instance,if desired, the vacuum may be shut off a moment before the pressure isconnected, or if desired for any reason both may be connectedsimultaneously for a short interval.

The scraper 64, with the rubber lip 65, serves to remove the solidmatter from the surface of the drum. The action of the scraper isgreatly facilitated by means of the jets or sprays of liquid which areforced out from the pipes 71, 7-1. These jets or sprays may be forcibleenough to entirely break up the layer of solid matter which hascollected and to wash it down the surface of the drum and down thesurface ofthe scraper into the trough 60 through which it 'may beconveyed to other parts of the plant for further treatment. The pressureof the rubber lip 65 against the drum may be regulated by means of theslidable weight 69, so that the scraper will act effectively without atthe same time subjecting the rubber lip and canvas to undue wear.

The pipe 74, if used, serves to break up and loosen any solid matterwhich may have passed beneath the scraper.

It will be understood that during the intermediate stages of thetreatment of ore by the cyanid process the purpose of dehydrating thepulp is to remove from it the solu-- tion which has become thoroughlysaturated with dissolved values. In many cases it is desirable afterthis saturated solution has been removed to again subject the ore to theaction of fresh solvent. This mixture of the ore with fresh solvent maybe very advantageously effected by introducing the solvent into thepipes 71, 71, and utilizing it in the form of jets or sprays to loosenand remove the material from the drum. When this is done the mixturefrom the trough 60 may be conducted directly to apparatus, such asagitating tanks for the dissolving of further values from the ore.

I do not claim as a part of my present invention the process referredto, as this is covered by my copending application entitled Process ofore treatment, filed November 29, 1910, Serial No. 594703.

What I claim is 1. The combination in a dehydrating mechanism, of atank, a drum framework mounted partly within the tank for rotation abouta horizontal axis and comprising an annular conduit, a filtering mediumfixedly mounted on the framework and forming a complete cylindersurrounding the conduit and closely adjacent thereto,means formaintaining partial vacuum in the conduit, ducts rigid with respect tothe framework and serving to directly connect sectoral parts of theinner surface of the filtering medium independently of each other withthe conduit, valves interposed respectively between the said sectoralparts of the filtering medium and the conduit, means operatingcontinuously to remove accumulated material from the uppermost partthereof, and means for automatically causing each valve to be closedduring'that part of'its revolution where it is adjacent the lastaforesaid means and to be open during the remainder of said revolution.

2. The combination in a dehydrating mechanism, of a tank, a drumframework mounted partly within the tank for rotation about a horizontalaxis and comprising two parallel annular conduits, a filtering mediumfixedly mounted on the framework and forming a complete cylindersurrounding the conduits and closely adjacent there to, means formaintaining partial vacuum in one conduit, means formaintaining pressurein the other conduit, ducts rigid with respect to the framework andserving to directly connect sectoral parts of the inner surface of thefiltering medium independently of each other with vacuum conduit, otherducts rigid with respect to the framework and serving to directlyconnect the said sectoral parts independently of each other With thepressure conduit, valves interposed respectively between the saidsectoral parts of the filtering medium and the said vacuum conduit,other valves interposed respectively between the said sectoral parts andthe said pressure conduit, means for automatically causing each of thefirst said valves to be open during the lower part of each revolutionand closed during the upper part, means operating continuously to removeaccumulated material from the uppermost part thereof, and means forautomatically causing each valve to be closed during that part of itsrevolution where it is adjacent the last aforesaid means and to be openduring the remainder of said revolution.

8. The combination in a dehydrating mechanism, of a tank, a drumframework mounted partly within the tank for rotation about a horizontalaxis and comprising an annular conduit, a filtering medium fixed withrespect to the framework and forming a complete cylinder surrounding theconduit and closely adjacent thereto, the said me dium being made up ofa plurality of separated sectoral sections, a plurality of frames forthe said sections respectively, the said frames being normally rigidlybut detachably connected -to the drum framework, means for maintaining apartial vacuum in the conduit, ducts rigid with respect to the frameworkand serving to directly connect the said sections of the filteringmedium independently of each other with the conduit, valves interposedrespectively between the said sections of the filtering medium and theconduit, means operating continuously to remove accumulated materialfrom the uppermost part thereof, and means for automatically causingeach valve to be closed during that part of its revolution where it isadjacent the last aforesaid means and to be open during the remainder ofsaid revolution.

4. The combination in a dehydrating mechanism, of a tank, a drumframework mounted partly within the tank for rotation about a horizontalaxis, a filtering medium fixed with respect to the framework and forminga complete cylinder, the said medium being made up of a plurality ofseparable sectoral sections, a plurality of frames for the said sectionsrespectively, normally rigidly but detachably connected to the drumframework and each having a set of grooves which extend longitudinallyof the drum and over which the filtering medium is stretched, the saidgrooves being closed at their ends and separated from each other byimperforate walls, a vacuum means, ducts rigid with the drum frameworkand each serving to directly connect the grooves of one set with thevacuum means independently of the grooves of the other set, and valveslocated respectively in the said ducts.

5. The combination in a dehydrating mechanism, of a tank, a drumframework mounted partly within the tank for rotation about a horizontalaxis and comprising an annular conduit, a filtering medium fixed withrespect to the framework and forming a complete cylinder surrounding theconduit and closely adjacent thereto; medium supporting frame elementsconnected to the drum framework and having sets of grooves which extendlongitudinally of the drum and over which the filtering medium isstretched, the said grooves being closed at their ends and separatedfrom each other by imperforate walls, means for maintaining a partialvacuum in the conduit, ducts rigid with the drum framework and eachserving to directly connect the grooves of one set with the conduitindependently of the grooves of the other sets, and valves locatedrespectively in the said ducts.

6. The combination in a dehydrating mechanism, of a tank, a drumframework mounted partly within the tank for rotation about a horizontalaxis, a filtering medium fixed with respect to the framework and forminga complete cylinder, the said ,medium being made up of a plurality ofsectoral sections, a plurality of frames for the said sectionsrespectively, normally rigidly but detachably Ennected to the drumframework and each having as a component part thereof a sheet of metalcorrugated longitudinally of the drum, the outer part of eachcorrugation being imperforate and the said filtering medium beingstretched over and between the corrugations, means for closing the endsof the spaces between.

the corrugations, and means for causing a partial vacuum in the spacesbetween the corrugations and the filtering medium.

7. In a dehydrating mechanism, the combination of a tank, a drumstructure mounted partly within the tank for rotation about a horizontalaxis and comprising two annular conduits, each provided with spacedapertures in its outer peripheral wall, means for maintaining partialvacuum within one conduit, means for maintaining pressure within theother conduit, a plurality of independent filtering elements rigidlysecured to the drum structure and cooperating to form a completecylindrical surface, the said elements being provided with passagewayshaving apertures adapted to register with the apertures in theperipheral walls of the conduits, valves adapted to close the aperturesin the vacuum conduit, other valves adapted -to close the aperture inthe pressure conduit, means for automatically causing each of the firstsaid valves to be open during the lower part of each revolution andclosed during the upper part, means operating continuously to removeaccumulated material from the uppermost part thereof, and means-forautomatically causing each valve to be closed during that part of itsrevolution where it is adjacent the last aforesaid means and to be openduring the remainder of said revolution.

8. In a dehydrating mechanism, the combination of a tank, a drumstructure mounted partly within the tank for rotation about a horizontalaxis and comprising an axle having therein two chambers, two sets ofhollow spokes, one set being connected with one axle chamber and theother set being connected with the other axle chamber, and two hollowannular rings, one connected with one set of hollow spokes and the"other with the other set of hollow spokes, each ring being made up of aplurality of sections eachof which at its center is secured to and incommunication with one of the spokes, a plurality of independentfiltering elements rigidly secured to the drum structure and cooperatingto form a complete cylindrical surface, means for automaticallyestablishingi communication between each filtering element independentlyof the others and the two annular rings alternately as the drumstructure is rotated, means for maintaining a vacuum within one axlechamber, one set of spokes and one annular ring, means for maintain-,ing a pressure the other axle chamber, the other set of spokes and theother annular ring, and means continuously engaging the cylindricalsurface formed by the filtering elements at points along the upper partof its path to remove accumulated material. 9. In a dehydratingmechanism, the combination of a tank, a drum structure rotatably mountedpartly within the tank and comprising an axle consisting of a centralpart and two end parts, each of which is provided with a chamberseparated from the central part, two annular hollow rings, hollow spokesfor establishing connection between each axle chamber and one of therings, and radially inward extending partitions 15 within the axlechambers between the points of connections of the spokes, means formaintaining a vacuum within one axle chamber and one ring, means formaintaining a pressure within the other axle chamber and the other ring,a filtering device connected with the rings, and means for automaticallyconnecting the filtering device alternately with the two rings.

10. In a dehydrating mechanism, the combination of a tank, a rotatabledrum structure comprising two annular hollow rings, a plurality offiltering sections mounted to rotate with the hollow rings, means formaintaining a vacuum within one hollow ring, means for maintaining apressure within the other hollow ring, means for automaticallyconnecting each filtering section independently of the othersalternately with the two hollow rings as the drum structure is rotated,and means for regulating the periods during which the filtering sectionsare connected with one or the other of the said rings.

11. In a dehydrating mechanism, the combination of a tank, a rotatabledrum structure comprising two annular hollow rings, a plurality offiltering sections mounted to r0- tate with the hollow rings, means formaintaining a vacuum within one'hollow ring, means for maintaining apressure within the other hollow ring, means for automaticallyconnecting each filtering section independently 0f the othersalternately with the two hollow rings as the drum structure is rotated,and means for regulating the, periods during which the filteringsections are connected with one or the other of the said rings, the saidmeans comprising rotatable valves provided with radial arms foractuating the same, pins to engage with the arms, slotted brackets forsupporting the pins, and devices for holding the pins in adjustedpositions in the said slots.

12. In a dehydrating mechanism, the combination of a tank, acontinuously moving filtering medium adapted to be submerged during apart of its movement in a body of pulp within the tank, means forremoving moisture from the pulp and collecting the solid matter thereofupon the surface of the filtering medium, means for loosening andreceiving the solid matter from the filtering .medium comprising a broadapron-like deflector having a flexible edge adapted to engage the saidmedium, means for yieldably holding the deflector against the medium,and means for adjusting the holding means to regulate the pressurebetween the deflector and the medium.

13. In a dehydrating mechanism, the combination of a tank, acontinuously moving filtering medium mounted to be submerged during apart of its movement in a mass of pulp Within the tank, means forremoving moisture from the pulp and collecting the solid matter thereofon the filtering medium, and means for loosening and receiving the solidmatter from the filtering medium comprising a movably mounted deflectoryieldingly engaging the medium, and devices for directing jets of liquidupon the medium simultaneously at points arranged along a plurality ofseparated lines parallel to and closely adjacent the said deflector toloosen the collected material and wash it down upon the said deflector.

14. In a dehydrating apparatus, the combination of a tank, a continuallymoving filtering medium arranged to be submerged during a part of itsmovement in a body of pulp within the tank, means for removing moisturefrom the pulp and collecting the solid matter thereof upon the surfaceof the filtering medium, means for removing the solid matter from thesurface of the filtering medium comprising a deflector engaging the saidmedium as it is moved, a device behind the deflector for directingstreams of liquid against the said medium, and a second deflectorengaging the said medium as it is moved at points in advance of thefirst deflector, and a common means for recelvlng material from the saiddeflectors.

15. In a dehydrating apparatus, the combination of a tank, a continuallymoving filtering medium arranged to be submerged during a part of itsmovement in a body of pulp within the tank, means for removing moisturefrom the pulp and collecting the solid matter thereof upon the surfaceof the filtering medium, means for removing the solid matter from thesurface of the filtering medium comprising a deflector engaging the saidmedium as it is moved, a device behind the deflector for directingstreams of liquid against the said medium, a second device in advance ofthe deflector for also directing streams of liquid against the saidmedium, and a second deflector engaging the said medium as it is movedat points in ad- Vance of the first deflector and in advance of thesecond liquid directing device, and a common means for receivingmaterial from the said deflectors.

In testimony whereof I aflix my signature in presence of two witnesses.

CYRUS ROBINSON.

Witnesses:

' II. J. G. MACKIE,

DAVID SCOTT.

